+ disallow taking the address of WebAssembly externref type

compiler/msg/errore.msg

@@ -1649,8 +1649,8 @@ parser_w_ignoring_published_property=03365_W_This property will not be published
 %
 # Type Checking
 #
-# 04132 is the last used one
-# type_w_dangerous_type_conversion=04132
+# 04133 is the last used one
+# type_w_dangerous_type_conversion=04133
 #
 % \section{Type checking errors}
 % This section lists all errors that can occur when type checking is
@@ -1875,7 +1875,7 @@ type_e_operator_not_supported_for_types=04053_E_Operation "$1" not supported for
 type_e_illegal_type_conversion=04054_E_Illegal type conversion: "$1" to "$2"
 % When doing a type-cast, you must take care that the sizes of the variable and
 % the destination type are the same.
-type_w_dangerous_type_conversion=04132_W_Type conversion between unrelated/incompatible types: "$1" to "$2"
+type_w_dangerous_type_conversion=04133_W_Type conversion between unrelated/incompatible types: "$1" to "$2"
 % The typecast is allowed for compatibility but types are unrelated or not compatible
 type_h_pointer_to_longint_conv_not_portable=04055_H_Conversion between ordinals and pointers is not portable
 % If you typecast a pointer to a longint (or vice-versa), this code will not compile
@@ -2108,6 +2108,8 @@ type_e_nested_procvar_to_funcref=04131_E_A nested function variable can not be a
 % Function references can live beyond the scope of the function they're contained in while
 % nested functions assigned to nested function variables can't. Due to this discrepancy
 % in design assigning a nested function variable to a function reference is forbidden.
+type_e_cannot_take_address_of_wasm_externref=04132_E_Cannot take the address of a WebAssembly externref
+% WebAssembly externref types don't have an in-memory representation and therefore, their address cannot be taken.
 %
 % \end{description}
 #

compiler/msgidx.inc

@@ -533,7 +533,7 @@ const
   type_e_constant_expr_expected=04052;
   type_e_operator_not_supported_for_types=04053;
   type_e_illegal_type_conversion=04054;
-  type_w_dangerous_type_conversion=04132;
+  type_w_dangerous_type_conversion=04133;
   type_h_pointer_to_longint_conv_not_portable=04055;
   type_w_pointer_to_longint_conv_not_portable=04056;
   type_e_cant_choose_overload_function=04057;
@@ -602,6 +602,7 @@ const
   type_e_cant_read_write_type_in_iso_mode=04129;
   type_w_array_size_does_not_match_size_of_constant_string=04130;
   type_e_nested_procvar_to_funcref=04131;
+  type_e_cannot_take_address_of_wasm_externref=04132;
   sym_e_id_not_found=05000;
   sym_f_internal_error_in_symtablestack=05001;
   sym_e_duplicate_id=05002;
@@ -1158,9 +1159,9 @@ const
   option_info=11024;
   option_help_pages=11025;
 
-  MsgTxtSize = 90693;
+  MsgTxtSize = 90752;
 
   MsgIdxMax : array[1..20] of longint=(
-    28,109,366,133,100,63,148,38,223,71,
+    28,109,366,134,100,63,148,38,223,71,
     65,20,30,1,1,1,1,1,1,1
   );

compiler/wasm32/cpunode.pas

@@ -34,6 +34,7 @@ implementation
     ncgadd, ncgcal,ncgmat,ncginl,
     
     nwasmbas,nwasmadd,nwasmcal,nwasmmat,nwasmflw,nwasmcon,nwasmcnv,nwasmset,nwasminl,nwasmld,
+    nwasmmem,
     { these are not really nodes }
     nwasmutil,
     { symtable }

compiler/wasm32/nwasmmem.pas

@@ -0,0 +1,59 @@
+{
+    Copyright (c) 1998-2023 by Florian Klaempfl and Nikolay Nikolov
+
+    Generate WebAssembly code for memory related nodes
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+ ****************************************************************************}
+unit nwasmmem;
+
+{$i fpcdefs.inc}
+
+interface
+
+    uses
+      node,nmem,ncgmem;
+
+    type
+
+      { twasmaddrnode }
+
+      twasmaddrnode = class(tcgaddrnode)
+        function pass_typecheck:tnode;override;
+      end;
+
+implementation
+
+    uses
+      verbose,
+      symcpu;
+
+    { twasmaddrnode }
+
+    function twasmaddrnode.pass_typecheck: tnode;
+    begin
+      Result:=inherited;
+      if is_wasm_externref(left.resultdef) then
+        begin
+          CGMessagePos(left.fileinfo,type_e_cannot_take_address_of_wasm_externref);
+          result:=nil;
+          exit;
+        end;
+    end;
+
+begin
+  caddrnode:=twasmaddrnode;
+end.

tests/test/wasm/twasmexternref2.pp

@@ -0,0 +1,16 @@
+{ %cpu=wasm32 }
+{ %fail }
+
+program twasmexternref2;
+
+procedure testproc;
+var
+  p: WasmExternRef;
+  q: Pointer;
+begin
+  { WasmExternRef cannot be address taken }
+  q := @p;
+end;
+
+begin
+end.